Leakproof seal for wick tubes



A. w. RICHARDSON 3,316,956 LEAKPROOF SEAL FOR WICK TUBES May 2,1967

Original Filed Feb. 11, 1964 United States Patent Ofiice 3,316,956 Patented May 2, 1967 3,316,956 LEAKPROOF SEAL FOR WICK TUBES Arthur Whittaker Richardson, New Malden, England, assignor to Karma (New Malden) Limited Continuation of application Ser. No. 343,976, Feb. 11, 1964. This application Apr. 4, 1966, Ser. No. 540,090 8 Claims. (Cl. 158-38) This application is a continuation of my prior application, Serial No. 343,976 filed February 11, 1964, and now abandoned.

The present invention relates to commonly referred to as the short drum or perforated shell or sleeve burners. Such burners comprise a pair of tubular perforated burner shells supported one about the other to define an annular combustion chamber therebetween.

More particularly, the invention relates to burners of this type having a plurality of wicks, known as multiwick burners. The wicks in such burners are each supported in a wick tube, the assembly of tubes being mounted conveniently in the form of a circle on a plate or dish member and adapted to be moved into and out of a series of conduits into the burning position beneath the drum burner or away from that position for the purposes of extinguishing the flame. The wicks at their lower ends are immersed in the liquid fuel supply and if the stove is accidentally overturned the liquid fuel can leak from the container along the annular space between the tubes and the conduits into the burner and, if it contacts any surface of sufficient temperature, ignite and cause a serious fire which will be fed continuously from the container until the fuel level falls below the lowermost tube.

According to the present invention the tubes carrying the wicks work in apacking mounted to prevent the liquid fuel leaking from the container around the tube, the packing allowing the tubes to slide up and down.

The packing may be provided either between the tube and the conduit on which it works or it may be provided on the inside of the liquid fuel reservoir.

A further embodiment arising from the provision of a liquid-tight seal is the provision of wide conduits in which the tubes operate to prevent or to reduce considerably the formation of carbon.

Advantageously, the short drum burner is provided with a down-draught trap, that is, an arrangement of air shields or screens such that a down-draught in the drum is at least substantially cancelled out in the vicinity of the flame by a down-draught in a passage provided by the air shields. The air shields conveniently consist of an upper air shield around the burner drum and a lower air shield extending beneath the drum and upwardly around it outside the upper air shield, the pets sage being between the two shields, which will normally be imperforate,

The invention will now be described with reference to the accompanying drawings in which:

FIGURE 1 shows diagrammatically in section a midiwick burner in accordance with the present invention; and

FIGURE 2 shows an alternative form of burner in accordance with the present invention.

There is provided above the top 1 of a reservoir tank containing kerosene or similar liquid fuel a plurality of guide tubes 2 each tube being fixedly secured as by turned out flanges 3 to the top VI of the reservoir, the joint being sealed to make it leak-proof. The tubes 2 carry at their upper end an annular trough 4 into which each tube 2 leads and in the base of which each tube 2 terminates.

The trough 4 supports the perforated burner shells 5 and 6 which at their upper end (not shown) carry a burners of the type radiant member which usually is in the form of a dome of wire mesh. This type of burner is more frequently associated with what is known as the drip-feed type of stove. In addition the shells carry an outer imperforate casing 7 which expands to the top of the shells 5 and 6 and lies substantially level with the bottom of the shells 5 and 6.

Mounted for axial movement up and down in each tube 2 is a wick 8, the wick 8 itself being carried in a wick tube 9. Each wick tube '9 is mounted upon a support means such as the plate 10. The plate 10 lies within the tank 1 and is constructed for adjustment upwardly and downwardly by being carried on the lower end 11 of a rack 12. The rack 12, which operates in a tube 13 sealed at its upper end 14, is controlled by a pinion 15 enclosed in a casing 16 sealed to the outer atmosphere but open to the tube 13 and to the tank 1. The pinion 15 is mounted upon a shaft 17 which projects outside the casing 16 and carries an operating handle. Operation of the handle enable all the wicks 8 and 9 simultaneously to be adjusted within the guide tubes 2.

The wick tubes 9 are open at their lower ends so that the Wicks can extend downwardly to be immersed in the kerosene or other liquid fuel in the reservoir so to permit the fuel to be fed up the wicks to the upper burning end. The wicks may be of any convenient material, for example asbestos or fiberglass. They can of course if desired be of cotton,

Mounted below the burner comprising the shells 5 and 6 and the casing 7 is an air shield 18 which for convenience and as shown is mounted positively on the lower end of the tube 13 and is apertured to allow the tubes 2 to pass therethrough. The air shield 18 is constructed and arranged to cooperate with the air shields constituted by easing 7 to balance out any down draughts occurring in the burner in the manner described above.

Whilst the shield as shown is entirely imperforate it will be realised that there may be provided apertures in the said shield but these should not be so large as to prevent a balancing effect being built up in the air shield in the event of any down draught in the burner.

Each wick tube 9 is shown mounted in a different manner to give the seal in accordance with the present invention. The wick tube 9a is mounted to slide in a sleeve 19 which constitutes an insert in the conduit 2, the arrangement being such that the wick tube 9a is a close sliding fit in the insert 19 which may be of metal, for example brass, or may be of any other material resistant to kerosene or other liquid fuel employed. For example, the sleeve could be made of polytetrafiuorethylene which is a resin offering very low resistance to anything in sliding contact therewith.

Wick tube 9b is mounted in the conduit 2 which has a restricted lower portion 20 in which the wick tube 912 operates. If desired the lower end of the conduit 2 can be lined with suitable material, for example the resin re ferred to above, or other material which allows the wick tube 91; to work freely and at the same time give a sulficiently small clearance to prevent leakage of fuel in the event of the stove being overturned.

The wick tube passes through a reduced portion of the conduit 2, the reduction being substantially a line reduction, that is to say the wick tube 9c only makes a line contact at 21 with the conduit 2, as shown Wick tube 9d is mounted in the conduit 2 which is of the same internal diameter for its Whole length and there is interposed between the wick tube 9d and the conduit 2 a coiled washer 22. This coiled washer may be in the form of a coiled spring or it may be formed of nonmetallic material, for example resin, and permits the wick tube 9d to work freely within the conduit 2.

In addition to the four methods of carrying the invention into effect a further construction is shown in FIG- URE 2. In this case the wick tube 9 is mounted to slide with ample clearance in the conduit 2 for the length of that conduit. Beneath the apertures cut in the top wall 1 of the tank there is secured a gasket plate 23. This gasket plate is held in position by a metal plate 24 so as to sandwich the gasket plate 23 between itself and the top 1 of the tank. The gasket plate 23 and metal plate 24 may conveniently be held in position by nut and bolt 25, The metal plate is cut to provide ample clearance for the passage of the wick tubes 9 but the gasket plate 23 is cut to provide a close sliding fit. This plate may be formed of any convenient material which is resistant to kerosene or other liquid fuel employed and is such as to permit the tube to slide easily therethrough and at the same time to provide a seal to prevent the leakage past of any fuel. The gasket plate may be made of artificial resin or synthetic rubber, for example the material known under the registered trademark neoprene. Another suitable material is sheet material known under the name Oakenstrong, this material being a compressed fibrous composition.

The gasket 23 or the restricted portions of the conduits 2 serve as an upper guide for the wick tubes 9 and permit of an accurate up and down movement within the conduits 2. By spacing the conduits with an ample clearance from the wicks 8 the formation of carbon is prevented or materially reduced.

Whilst five methods have been shown of carrying the invention into effect it will be realised that the invention is not limited to the five constructions and other means may be employed of carrying the invention into effect, for example the area enclosed by the plate 10 and the periphery described by the conduit 2 may be wholly enclosed, for example by a collapsible bellows again made of suitable material resistant to the liquid fuel and flexible. Thus one end of a short sleeve of neoprene may be secured in liquid tight manner to the periphery of the plate 10, the other end being secured in liquid tight manner to the inside of the top 1 of the fuel tank. Adjustment of the wick tubes is unalfected since as the plate 10 is moved up and down by the handle provided the sleeve will collapse or expand as required. Alternatively the plate 10 may form the lower end of a metal bellows, the upper end of which sealingly engages the inside of the tank around the conduits 2.

I claim:

1. A liquid-fuel burner having a pair of tubular burner shells, means supporting the burner shells one about the other to define an annular combustion chamber therebetween, a container for liquid fuel beneath the burner shells, said container having a top Wall, a plurality of annularly arranged conduits extending from the top wall of the fuel container to between the burner shells, a wick tube received coaxially within each conduit, a wick held within each wick tube and projecting slightly thereabove, the wick tubes having a diameter substantially less than at least the upper inside portion of the conduit tubes to provide an annular clearance therebetween of sufficient radial extent to prevent or materially reduce the formation and deposit of carbon on and adjacent the projecting portion of the wick and the upper end of the wick tubes and the conduit tubes, the wicks having lower ends extending into the fuel container, means connecting the wick tubes for axial movement together within the conduits and adapted to withdraw the projecting wick portions to within the conduit tubes, and means located at the lower end of each conduit forming a sliding seal around each wick tube and spacing the same from the upper inside portion of the conduit tubes to prevent fuel from flowing in the annular clearance between the wick tube and the conduit in which it is received and to maintain said annular clearance.

2. A liquid-fuel burner as claimed in claim 1 in which the means forming a seal comprises an elongate sleeve sealingly mounted in the lower end of each conduit in said clearance, the sleeve slidingly receiving the associated wick tube in close fitting sealing relationship.

3. A liquid-fuel burner as claimed in claim 1 in which the means forming a seal comprises each conduit having a portion at the lower end thereof of sufficiently reduced diameter such that said portion slidingly and sealingly receives the associated wick tube.

4. A liquid-fuel burner as claimed in claim 1 in which the means forming a seal comprises each conduit having a substantial line restriction near the lower end thereof such that the restriction slidingly and sealingly receives the associated wick tube and makes line contact therewith.

5. A liquid-fuel burner as claimed in claim 1 in which the means forming the seal comprises a helical washer at the lower end of each conduit in said clearance, the washer slidingly receiving the associated wick tube in close fitting sealing relationship.

6. A liquid-fuel burner as claimed in claim 1 in which the means forming a seal comprises a gasket secured to the inside face of a wall of the fuel container from which the conduits extend, the gasket having apertures which make a slidingseal with said wick tubes.

7. A liquid-fuel burner as claimed in claim 1 wherein said means connecting the wick tubes for axial movement comprises support means disposed in the container in spaced relationship with said top wall, the wick tubes being fixedly connected to the support means, and means connected to said support means and extending centrally of the conduits to the exterior of the top wall for moving said support up and down so as to effect movement of the wick tubes within the conduits, the point of seal between the wick tubes and the conduits serving as alignment guides for the wick tubes.

8. A liquid-fuel burner as claimed in claim 1 further including an air shield partially surrounding said burner shells and extending therebeneath, said shell having aper-. tures through which said conduits extend whereby said air shield balances out any down-draughts which may be created in said combustion chamber.

No references cited.

FREDERICK KETTERER, Primary Examiner. 

1. A LIQUID-FUEL BURNER HAVING A PAIR OF TUBULAR BURNER SHELLS, MEANS SUPPORTING THE BURNER SHELLS ONE ABOUT THE OTHER TO DEFINE AN ANNULAR COMBUSTION CHAMBER THEREBETWEEN, A CONTAINER FOR LIQUID FUEL BENEATH THE BURNER SHELLS, SAID CONTAINER HAVING A TOP WALL, A PLURALITY OF ANNULARLY ARRANGED CONDUITS EXTENDING FROM THE TOP WALL OF THE FUEL CONTAINER TO BETWEEN THE BURNER SHELLS, A WICK TUBE RECEIVED COAXIALLY WITHIN EACH CONDUIT, A WICK HELD WITHIN EACH WICK TUBE AND PROJECTING SLIGHTLY THEREABOVE, THE WICK TUBES HAVING A DIAMETER SUBSTANTIALLY LESS THAN AT LEAST THE UPPER INSIDE PORTION OF THE CONDUIT TUBES TO PROVIDE AN ANNULAR CLEARANCE THEREBETWEEN OF SUFFICIENT RADIAL EXTENT TO PREVENT OR MATERIALLY REDUCE THE FORMATION AND DEPOSIT OF CARBON ON AND ADJACENT THE PROJECTING PORTION OF THE WICK AND THE UPPER END OF THE WICK TUBES AND THE CONDUIT TUBES, THE WICKS HAVING LOWER ENDS EXTENDING INTO THE FUEL CONTAINER, MEANS CONNECTING THE WICK TUBES FOR AXIAL MOVEMENT TOGETHER WITHIN THE CONDUITS AND ADAPTED TO WITHDRAW THE PROJECTING WICK PORTIONS TO WITHIN THE CONDUIT TUBES, AND MEANS LOCATED AT THE LOWER END OF EACH CONDUIT FORMING A SLIDING SEAL AROUND EACH WICK TUBE AND SPACING THE SAME FROM THE UPPER INSIDE PORTION OF THE CONDUIT TUBES TO PREVENT FUEL FROM FLOWING IN THE ANNULAR CLEARANCE BETWEEN THE WICK TUBE AND THE CONDUIT IN WHICH IT IS RECEIVED AND TO MAINTAIN SAID ANNULAR CLEARANCE. 